A high-resolution shallow marine record of the Toarcian (Early Jurassic) Oceanic Anoxic Event from the East Midlands Shelf, UK

Caswell, Bryony A.; Coe, Angela L.

doi:10.1016/j.palaeo.2012.09.021

Cited by 33 publications

(14 citation statements)

References 53 publications

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“…Most of these species also became regionally extinct [33], whereas others migrated into nearby basins where environmental conditions were more hospitable. For instance, the gastropods Levipleura blainvillei and Ptychomphalus expansus , which disappear from the Cleveland Basin after the extinction, occur in the falciferum zone of the adjacent East Midlands Shelf [102], and the deep infaunal suspension feeding bivalve Pholadomya ambigua occurs in the falciferum zone of central Spain [103]. Others, like the pectinids Pseudopecten equivalvis and Camptonectes subulatus , are found in middle-upper Toarcian sediments of Spain and Greenland [91].…”

Section: Discussionmentioning

confidence: 99%

The Impact of Global Warming and Anoxia on Marine Benthic Community Dynamics: an Example from the Toarcian (Early Jurassic)

et al. 2013

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The Pliensbachian-Toarcian (Early Jurassic) fossil record is an archive of natural data of benthic community response to global warming and marine long-term hypoxia and anoxia. In the early Toarcian mean temperatures increased by the same order of magnitude as that predicted for the near future; laminated, organic-rich, black shales were deposited in many shallow water epicontinental basins; and a biotic crisis occurred in the marine realm, with the extinction of approximately 5% of families and 26% of genera. High-resolution quantitative abundance data of benthic invertebrates were collected from the Cleveland Basin (North Yorkshire, UK), and analysed with multivariate statistical methods to detect how the fauna responded to environmental changes during the early Toarcian. Twelve biofacies were identified. Their changes through time closely resemble the pattern of faunal degradation and recovery observed in modern habitats affected by anoxia. All four successional stages of community structure recorded in modern studies are recognised in the fossil data (i.e. Stage III: climax; II: transitional; I: pioneer; 0: highly disturbed). Two main faunal turnover events occurred: (i) at the onset of anoxia, with the extinction of most benthic species and the survival of a few adapted to thrive in low-oxygen conditions (Stages I to 0) and (ii) in the recovery, when newly evolved species colonized the re-oxygenated soft sediments and the path of recovery did not retrace of pattern of ecological degradation (Stages I to II). The ordination of samples coupled with sedimentological and palaeotemperature proxy data indicate that the onset of anoxia and the extinction horizon coincide with both a rise in temperature and sea level. Our study of how faunal associations co-vary with long and short term sea level and temperature changes has implications for predicting the long-term effects of “dead zones” in modern oceans.

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Section: Discussionmentioning

confidence: 99%

The Impact of Global Warming and Anoxia on Marine Benthic Community Dynamics: an Example from the Toarcian (Early Jurassic)

et al. 2013

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“…P. dubius is the only abundant bivalve found during the most reducing conditions of the Toarcian OAE and other Mesozoic periods, indicating that it was better adapted to deoxygenation. Shallower water areas could have provided new recruits for the bivalve populations (Caswell and Coe, 2012).…”

Section: Discussionmentioning

confidence: 99%

Primary productivity controls on opportunistic bivalves during Early Jurassic oceanic deoxygenation

Caswell¹,

Coe²

2013

Geology

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Severe paleoclimatic change during the Toarcian (Early Jurassic) oceanic anoxic event (OAE) was characterized by a negative δ 13 C excursion, increased weathering, higher seawater temperatures, oceanic deoxygenation, and mass extinction. We present abundance and size data (n ≈ 36,000) for the two dominant epifaunal bivalve species from the Toarcian OAE, Yorkshire, UK. We statistically correlate the biotic data with geochemical proxies for environmental change and show that our results are comparable with changes in present-day ecosystems affected by hypoxia. Bositra radiata dominated during declining oxygen levels immediately before the Toarcian OAE sensu stricto, and shell size doubled when δ 13 C org was decreasing, indicating a connection with primary productivity. Small Pseudomytiloides dubius dominated during the Toarcian OAE and varied sharply in abundance, indicating that it was highly opportunistic. P. dubius shell size is strongly related to Mo concentration, [Mo]; this indicates a relationship between size and N 2 -fi xing primary productivity via [Mo] limitation. A secondary factor contributing to small shell size was lower oxygen levels. After the Toarcian OAE diversity increased, P. dubius was less abundant and shell size doubled, indicating that bivalve populations were less limited by resources and conditions were more favorable. Size frequency distributions show that bothToarcian species had short life spans, rapid generation times, high recruitment, and high juvenile mortality. The opportunist Mulinia lateralis is a present-day analog for P. dubius. This research provides a case study for the long-term impacts of deoxygenation upon marine ecosystems, including that being observed today.

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“…Lower Jurassic rocks include a number of prominent carbon isotope excursions including one during the Toarcian Oceanic Anoxic Event (e.g., Jenkyns 1988;Hesselbo et al 2000aHesselbo et al , 2007Pálfy and Smith 2000;van de Schootbrugge et al 2005a;Gómez et al 2008;Suan et al 2008Suan et al , 2011Littler et al 2010;Korte and Hesselbo 2011;Silva et al 2011;Caswell and Coe 2012;Riding et al 2013;Kemp and Izumi 2014;Krencker et al 2014;Ait-Itto et al 2017;Arabas et al 2017;Bougeault et al 2017;Menini et al 2019;Mercuzot et al 2019). The TOAE has also been reported from Argentina (Al-Suwaidi et al 2010, 2016Mazzini et al 2010) and Chile (Fantasia et al 2018).…”

Section: Carbon Isotope Recordmentioning

confidence: 99%

First steps in reconstructing Early Jurassic sea water temperatures in the Andean Basin of northern Chile based on stable isotope analyses of oyster and brachiopod shells

2019

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The stable isotope (δ 13 C, δ 18 O) composition of a collection of Lower Jurassic brachiopods and oysters from the Andean Basin of northern Chile was analyzed. The results allow the first reconstruction of absolute water temperatures for several ammonite zones in the Lower Jurassic of South America. The temperature record starts with comparatively high values in the Late Sinemurian (average: 27.0°C; Raricostatum Zone). Just before the Sinemurian-Pliensbachian transition, temperatures dropped to an average of 24.3°C. The lowest temperature value in the dataset was recorded for a brachiopod shell of the latest Pliensbachian Spinatum Zone (19.6°C). No data are available for the Early Toarcian, but results for the late Toarcian show again comparatively warm conditions (average: 24.4°C; Thouarsense-Levesquei zones). Even though more material and analyses are necessary to corroborate the recorded temperatures, the present dataset seems to indicate the global nature of the Late Pliensbachian Cooling Event. In contrast, the global warming during the Toarcian Oceanic Anoxic Event has not been recorded due to a lack of Early Toarcian material. The δ 13 C record of brachiopods and oysters documents a gradual increase in values representing background conditions. Oyster shells were used for high-resolution stable isotope analyses and show seasonal temperature fluctuations over a period of around 3 years in the life time of the bivalves. If explained only by temperatures, the δ 18 O values point to a minimum estimate for the seasonality in the late Toarcian of slightly more than 3°C.

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A high-resolution shallow marine record of the Toarcian (Early Jurassic) Oceanic Anoxic Event from the East Midlands Shelf, UK

Cited by 33 publications

References 53 publications

The Impact of Global Warming and Anoxia on Marine Benthic Community Dynamics: an Example from the Toarcian (Early Jurassic)

The Impact of Global Warming and Anoxia on Marine Benthic Community Dynamics: an Example from the Toarcian (Early Jurassic)

Primary productivity controls on opportunistic bivalves during Early Jurassic oceanic deoxygenation

First steps in reconstructing Early Jurassic sea water temperatures in the Andean Basin of northern Chile based on stable isotope analyses of oyster and brachiopod shells

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